feat: add dev make target — infra in Docker, server+worker run locally

- Add EXTERNAL listener on port 9093 to Kafka so local processes can connect
- Add KAFKA_BROKERS=localhost:9093 to .env.example
- Add dev/dev-infra-up/dev-infra-down targets to Makefile

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/.env.example

@@ -13,6 +13,9 @@ JWT_REFRESH_DURATION=720h
 PORT=8080
 ALLOWED_ORIGINS=http://localhost:3000
 
+# Kafka (localhost:9093 for local dev, kafka:9092 when running inside Docker)
+KAFKA_BROKERS=localhost:9093
+
 # External APIs
 OPENAI_API_KEY=your-openai-key
 PEXELS_API_KEY=your-pexels-key

backend/Makefile

@@ -1,4 +1,4 @@
-.PHONY: run run-worker test test-integration lint migrate-up migrate-down migrate-create migrate-status docker-up docker-down docker-logs docker-logs-worker
+.PHONY: run run-worker dev dev-infra-up dev-infra-down test test-integration lint migrate-up migrate-down migrate-create migrate-status docker-up docker-down docker-logs docker-logs-worker
 
 ifneq (,$(wildcard .env))
   include .env
@@ -12,6 +12,19 @@ run:
 run-worker:
 	go run ./cmd/worker
 
+# Start only infra (postgres, kafka) in Docker, run server + worker locally
+dev: dev-infra-up
+	@trap 'kill 0' INT; \
+	go run ./cmd/server & \
+	go run ./cmd/worker & \
+	wait
+
+dev-infra-up:
+	docker compose up -d postgres kafka kafka-init
+
+dev-infra-down:
+	docker compose stop postgres kafka kafka-init
+
 # Tests
 test:
 	go test ./... -v -race -count=1

backend/docker-compose.yml

@@ -4,17 +4,19 @@ services:
     environment:
       KAFKA_NODE_ID: 1
       KAFKA_PROCESS_ROLES: broker,controller
-      KAFKA_LISTENERS: PLAINTEXT://:9092,CONTROLLER://:9093
-      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka:9092
-      KAFKA_CONTROLLER_QUORUM_VOTERS: 1@kafka:9093
+      KAFKA_LISTENERS: PLAINTEXT://:9092,EXTERNAL://:9093,CONTROLLER://:9094
+      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka:9092,EXTERNAL://localhost:9093
+      KAFKA_CONTROLLER_QUORUM_VOTERS: 1@kafka:9094
       KAFKA_CONTROLLER_LISTENER_NAMES: CONTROLLER
-      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,CONTROLLER:PLAINTEXT
+      KAFKA_INTER_BROKER_LISTENER_NAME: PLAINTEXT
+      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,EXTERNAL:PLAINTEXT,CONTROLLER:PLAINTEXT
       KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
       KAFKA_TRANSACTION_STATE_LOG_REPLICATION_FACTOR: 1
       KAFKA_TRANSACTION_STATE_LOG_MIN_ISR: 1
       CLUSTER_ID: "MkU3OEVBNTcwNTJENDM2Qg"
     ports:
       - "9092:9092"
+      - "9093:9093"
     healthcheck:
       test: ["CMD-SHELL", "kafka-topics --bootstrap-server localhost:9092 --list || exit 1"]
       interval: 10s